Date: Sat, 12 May 2001 16:14:29 -0600
Reply-To: Alfred Bagdan <abagdan@powersurfr.com>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Alfred Bagdan <abagdan@powersurfr.com>
Subject: Re: AFM Testing?
Content-Type: text/plain; charset="iso-8859-1"
Steve,
My AFM tests similar to yours. When looking closely (shine a strong light
at an angle), I noticed a hairline crack, right where the resistance jumps.
I have been driving like that for a while now, I'm surprised, because there
seem to be no problems, and the gas mileage is good too. I ordered a new
AFM meter though, just in case.
Alfred
85 Westy
----- Original Message -----
From: Steve Gough
To: vanagon@GERRY.VANAGON.COM
Sent: Saturday, May 12, 2001 1:25 PM
Subject: Re: AFM Testing?
Joe,
I'm sure I'm checking it right. Behaves the same way both by checking at
pins 2-3 (center two)
and by touching the board.
Here are the values, in kohms, measured both at the pins and by putting a
probe on the carbon track where the wiper are contact would be (and closest
to the taps, because the carbon track obviously has its own
resistance: Here's what I get:
pins 3-4 on carbon track
closed 500 500
1 1100 1100
2 1100 1500
3 1100 1500
4 1100 1800
5 1100 1200
6 1000 1100
7 950 1000
8 900 1000
9 800 1000
open 300 700
----- Original Message -----
From: Joe Romas
To: Steve Gough
Sent: Saturday, May 12, 2001 2:05 PM
Subject: Re: AFM Testing?
Steve,
Something dosen't sound right! It should keep rising in a steady line with
no dips or rises and keep going up untill it reaches the end. Are you
metering it at the pins or somewhere on the board?
Joe
----- Original Message -----
From: Steve Gough
To: Joe Romas
Sent: Saturday, May 12, 2001 2:56 PM
Subject: Re: AFM Testing?
Thanks, Joe.
What's wierd to me is that neither unit shows a steady increase or decrease
in resistance as the flap is opened. More like a "hump", i.e. resistance
slowly
rises until about half open, and then falls again. It's lowest at either
end of the
travel. Make any sense?
Steve
----- Original Message -----
From: Joe Romas
To: Steve Gough
Sent: Saturday, May 12, 2001 12:59 PM
Subject: Re: AFM Testing?
Steve,
The one with the drop-outs is bad! The resistance should rise steadilly as
you move the arm from idel position. When the computer gets to the
"drop-outs" it sees it as a lot of air and adds more fuel and that's when
things go south as far as running go.
Joe
----- Original Message -----
From: Steve Gough
To: vanagon@GERRY.VANAGON.COM
Sent: Friday, May 11, 2001 4:06 PM
Subject: AFM Testing?
Dear List,
I'm trying to tell if I need a new air flow meter for my '86 Vanagon.
Can anybody enlighten me on how resistance should change
as the vane moves? My manuals (even Probst) are vague.
I have two AFM's in hand. Both show similar resistance changes
with movement, but one seems to have some drop-outs.
Couldn't locate anything in the archives.
thanks,
Steve